xf.li | bdd93d5 | 2023-05-12 07:10:14 -0700 | [diff] [blame^] | 1 | /* low level locking for pthread library. Generic futex-using version. |
| 2 | Copyright (C) 2003-2016 Free Software Foundation, Inc. |
| 3 | This file is part of the GNU C Library. |
| 4 | Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003. |
| 5 | |
| 6 | The GNU C Library is free software; you can redistribute it and/or |
| 7 | modify it under the terms of the GNU Lesser General Public |
| 8 | License as published by the Free Software Foundation; either |
| 9 | version 2.1 of the License, or (at your option) any later version. |
| 10 | |
| 11 | The GNU C Library is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 14 | Lesser General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU Lesser General Public |
| 17 | License along with the GNU C Library; if not, see |
| 18 | <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #include <errno.h> |
| 21 | #include <sysdep.h> |
| 22 | #include <lowlevellock.h> |
| 23 | #include <sys/time.h> |
| 24 | #include <atomic.h> |
| 25 | |
| 26 | void |
| 27 | __lll_lock_wait_private (int *futex) |
| 28 | { |
| 29 | if (*futex == 2) |
| 30 | lll_futex_wait (futex, 2, LLL_PRIVATE); /* Wait if *futex == 2. */ |
| 31 | |
| 32 | while (atomic_exchange_acq (futex, 2) != 0) |
| 33 | lll_futex_wait (futex, 2, LLL_PRIVATE); /* Wait if *futex == 2. */ |
| 34 | } |
| 35 | |
| 36 | |
| 37 | /* This function doesn't get included in libc. */ |
| 38 | #if IS_IN (libpthread) |
| 39 | void |
| 40 | __lll_lock_wait (int *futex, int private) |
| 41 | { |
| 42 | if (*futex == 2) |
| 43 | lll_futex_wait (futex, 2, private); /* Wait if *futex == 2. */ |
| 44 | |
| 45 | while (atomic_exchange_acq (futex, 2) != 0) |
| 46 | lll_futex_wait (futex, 2, private); /* Wait if *futex == 2. */ |
| 47 | } |
| 48 | #endif |